\Ma*drier"\, n. [F., from Sp. madero, or Pg. madeiro,
fr. Sp. madera wood for building, timber, Pg. madeira, L.
materia stuff, materials, lumber. See {Matter}.]
A thick plank, used for several mechanical purposes;
especially:
(a) A plank to receive the mouth of a petard, with which it
    is applied to anything intended to be broken down.
(b) A plank or beam used for supporting the earth in mines or
    fortifications.